It is known to decorate the surface of a forming article made of synthetic resin using a transfer technique. However, it is difficult, in the conventional method, to apply this technique to such article having a deep inner surface or a large size in length as a dish or a cup. Further, it is also difficult to transfer to a cubically formed surface having a complicated concave, convex or spherical surface, etc., supplying a transfer paper smoothly and adhering it.